WELDING CHARACTERISTICS OF PLS U10 UNDULATOR VACUUM CHAMBER

摘要

With the U10 undulator beamline at PLS, a newly designed vacuum chamber for insertion device is needed to replace an existing straight vacuum chamber in the storage ring. We have designed and fabricated a 4.44 m long straight vacuum chamber made of Al alloy A5083-H321. The gas tungsten arc welding parameters were firstly optimised with a test chamber and then applied into the main chamber. The chamber performances were achieved with leak rate less than 10~(-10) Torr-l/sec and vacuum pressure below 10~(-10) Torr with bakeout. The mechanical integrity of welded chamber was maintained without severe weld discontinuities as in porosity, incomplete fusion or cracks.